Thymoma is a type of tumor that originates in the thymus, a small organ located in the chest that plays a crucial role in the immune system. These tumors are usually slow-growing and can be benign (non-cancerous) or malignant (cancerous). Thymomas are often associated with autoimmune diseases, such as myasthenia gravis, which affects muscle strength. Diagnosis of thymoma typically involves imaging tests like CT scans or MRI to visualize the tumor, followed by a biopsy to confirm its nature. Treatment options may include surgery, radiation therapy, or chemotherapy, depending on the tumor's size and whether it has spread to other areas.